While PDX-published games may suffer from the decouplement of features between DLCs, at the very least PDS-developed games have a built-up expertise when it comes to managing this.
As for MMO model, it’s a hard sell because purchased things get made “free” for new comers. It’s one of the crux that EU4 faced when they rolled many DLC features into the base game.
Like
if(true)
but with side effects.